Things are Shaking Up at Apple!

In its biggest top-level reorder since Tim Cook took over as chief executive last year, Apple’s (NASDAQ:AAPL) chief of iPhone software and its head of retail are set to leave the company next year. Apple said in a press release on Monday that Scott Forstall, who helped build the original architecture of the Mac operating system and is the head of iOS, will leave next year. He will serve as an advisor to Cook in the interim. In addition, John Browett, who only took over as retail chief earlier this year, will also leave, and the search for his replacement is already underway. In the meantime, the retail team will report directly to Cook.

Forstall’s departure will transfer some of his responsibilities to other executives, including Eddy Cue, the current head of the company’s Internet services. Cue will take over the development of Siri and Apple maps, both technologies that have attracted the company outside criticism over the past few months. Jony Ive, the head of Apple’s industrial design, will also take on more software responsibilities, while Craig Federighi, previously in charge of Mac software development, will lead the development of iOS.

Browett has also faced some criticism during his time at the company since taking over in April. In August, Apple apologized to its retail workers for a plan to cut back on staffing at its stores.

Apple said in Monday’s release that the management changes would “encourage even more collaboration” at the company.

“We are in one of the most prolific periods of innovation and new products in Apple’s history,” Cook said in the statement. “The amazing products that we’ve introduced in September and October, iPhone 5, iOS 6, iPad mini, iPad, iMac, MacBook Pro, iPod touch, iPod nano, and many of our applications, could only have been created at Apple and are the direct result of our relentless focus on tightly integrating world-class hardware, software, and services.”